Modifying castor oil



Patented Aug. 11 i942 2,292,902 a g monmrnvs casroa on.

No Drawing. Application in... 15, 1939,

, Serial No. 90,251

f-i Claims. (01. 260-398) This invention or discover relates to modifyquantity used, would alone direct the result want- .ing castor oil;fand it comprises a methodoi modied- It was my discovery that the two catalysts i'ying castor oil to make it miscible with mineral used together exercise 'an efl'ect which is ;more lubricating oils and also, with a more drastic than their sum. This compound catalyst of sul- UNITED STATES PATENT" oFFica treatment, of converting it into an excellent dry- 5 furic acid or sodium bisulfatefcarried. by a clay mg oi1,'wherein th castor ,oil is heated in the gives good results, but after the action ,is eipresence of a dissolved'camphor sulfonic acid, fected, it is necessary to get rid of the suspended the amount or catalyst present and the condimineral matter. Properly usedhowever, the

tions of heating sometimes being merely enough compound catalyst does not give discoloring eitomakethecastor oil miscible with mineral lubrifects, develop acidity or eataLvze pyrolysis, and eating oil and sometimes being sufficient to imdoes give high rade drying oil of commercial part full drying properties; all as more fully quality. I 1 I hereinafter set forth and as claimed. The drying .oil produced by the catalysis has Castor oil contains ricinolein, the glyceride of much the character of tung oil and in varnishes ricinoleic acid. This vdiiiers from other oleic l5 and paints it dries to a more waterproof m that t arrie an alcoholic hydroxyl than is given by linseed oil The oil, however', group. Castor oil is 01 alcoholic character. It does not have the annoying gelating action of is more miscible with the alcohols than are other tung oil d it ca be heated, as in bodyi fatty oils and itis correspondingly less miscible without the necessity for adulterants such asl with other oils and hits and with petroleum hyin ,Or adm x e th linseed drocarbons. It doesnot mix readily with the 4 I have now 'found that I can produce similar ordinary petroleum lubricating oils. When results and even a better quality-of oil by the blends are wanted, in order-to make it miscible, llse'ef a trace of one or the camphor suli'onic it is often heated th n y tal t mostly acids These happen to-be soluble in hot castor acids. By heatingwith almost any acid, 'miscioil, dissolving readily in castor oilat a compara bility can be conferred. The nature of the inf i temperature. say 240 E. Few other temal changes: taking place in securing misciacid catalysts, especiallythe organicacid com- "bility is not well unde tood and pr y t P w l dissolve'm 093ml 1 Most the,

' sulfonic acids carrying along hydrocarbon side arenot simple. The alcoholic nature, however,

is obviated in some way. In these methods? 15 3o chain are soluble in other oils but not in caster an object to heat only enough to secure misci- -oil. *Ii'used in catalyzing castor oil, either in bility. Other changes are not wanted. It is a i miscible or in dehydr ylatine. they diflicult to preserve alight color. must sim ly be kept stirredin. As a matter or By carrying the action oithe acid further, i athey are better used n y legous to the hydroxyl groups of the ricinolein are removed 5' that of (my p tented pr adsorbed in an as H2O leaving a new unsaturated bond. The oil e rthy carrier.

is now drying; a property 01 course not wanted Camphor sulionic acid is effective in producing in lubricants. It is diflicult, however, to catalyze atalysis in amounts as small as -I pe ent y the oil in such a way as to effect only this change; weight or less. Larger amounts may be used, so as not to injuriously affect the colorrand de- 40 butgenerally ve no better results than amounts sirable properties of the castor oil. Great tech- 0f h Order Of P centn s lving 0.1 nical dimculties have been encountered in the per-cent or commercial camphor s'ulionic acid in effort to convert castor oil into areally good comcastor oil at 240F. and then heating, there. is mercially acceptable drying oil. Dehydroxyla- 7 no noticeable action until the temperature tion can be effected by various specially treated reaches about 440 F. There is then a quick rebleaching earths-but these are diflicult tore-5', action',-which.. is sometimes violent. This action move mar- B is attended by an evolution of- Ha0 vapors; The

In aanot-her and I have described and claimed-a way oieflectinga Scare inoperation is necessary. .The 'ca'mphor-sulclean conversion of castor oil into a high grade ionicia'cid is in solution in all parts of thebody drying oil of commercial quality. This way in v of oil and reactionmay take place with some,

substance is to catalyze the hot oil with sulfuric violence when the critical temperature is reached. -acid or'sodium 'bisulfatein extremelyrsmall T'The critical temperatureis somewhere around quantities supported on an absorbent earth or 440'F. However, a large body of oil cannot be 1 "ritij1ratentub;2,140,271,.rj wholebodyof oil eflervescesa'nd-considerable:

clay. Neither the clay nor the acid, inthe 'heated uniformly and suddenly to the critical Z acids.

temperature, and the conditions of heating on a commercial scale therefore afiord control. After the conversion is complete, the oil can be cooled and neutralized if this be desired. The amount of acid is so small, however,that it does not noticeably change the acid value of the oil, nor is it harmful in varnishes and paints made with the aid of the new oil. It does not aifect pigments. Mostly, it can be simply allowed to remain in th oil.

After the hydroxyl groups are removed, the, oil can be bodied in the usual way; that is, by heating to temperatures of the order of 500 to 600 F. The presence of camphor sulfonic acid does not seem injurious in bodying; in fact itis my belief that the bodying. is quicker in its presence than in its absence.

Camphor sulfonic acids are commercial products, being sometimes known as Reychlers Their exact structure is somewhat uncertain. Camphor is a bridged ring carrying a methyl side chain; the ring having six members including one CO group. Some formulae for Reychlers acids represent sulfonation as being in the methyl side chain while'others represent the sulfonic group as being attached to a CH group adjacent the CO group. However, for the present purposes the structure is unimportant; the fact is that the commercial Reychlers acids are soluble in warm-caster oil and have the described catalyzing action.

In a specific embodiment of the present invention, making castor oil readily miscible with lu- 'bricating oils, the castor oil is heated with 0.05 per cent camphor sulfonic acid to a temperature of 350 to 400 F. for 3 hours. The castor oil is made miscible without any substantial'change in its acid value or other chemical constants.

It does not acquire drying properties unfitting itfor use as a lubricant.

In converting castor oil to a commercial drying oil analogous to tung oil and having much the same properties, to a batch of 2000 pounds of good, clean .castor oil, camphor sulfonic acid is added in the amount of 2 pounds; this being 0.1 per cent. The oil is heated in the ordinary way and in the ordinary types of kettle. V'hen the temperature reaches 240-250 F. the camphor sulfonic acid goes into solution. The oil is well stirred to make it uniform and then heated further. As the oil reaches a temperature somewhere around 440" F., energetic reaction takes place attended with the formation of steam bubbles. With a small batch and quick heating evolution of steam may be rapid and special precautions must be taken to avoid loss by priming. With larger batches, such as the one just stated, no special precautions are necessary. Heating under vacuum is not necessary, although it may be done. When the formation of steam bubbles ceases the oil may be cooled and given an alkaline wash toneutralize and remove the camphor sulfonic acid. This is not necessary, however, as previously stated. The oil may be marketed and used for most purposes without removal of the catalyst.

Although castor oil is a highly viscous oil, the product obtained by the catalysis is rather thin and mobile; somewhat resembling raw tung oil.

For commercial purposes it is generally desirable to body it. Bodying may be carried to any extent desired, even to the thick body characterizing stand oils and lithographers varnish. In bodying, the oil is heated to a temperature between 550" and 600 F. for some hours; the length of time depending'on the body desired. The camphor sulfonic acid may or may not be removed prior to bodying, Or it may be neutralized.

What I claim is: 1. In modifying castor oil,"the process which comprises heating it in the presence of a minor amount of dissolved camphor sulfonic acid for a period at least sufl'icient to make the oil miscible with mineral lubricating oils.

2. In producing drying oil from castor oil, the process which comprises dissolving a minor amount of camphor sulfonic acid in the oil and heating the oil to a temperature of the order of 440 F. I

3. The process of claim 2, wherein the camphor sulfonic acid is added to the oil in an amount of the order of 0.1 per cent by weight.

4. In producing drying oil from 'castor oil, the process which comprises dissolving a minute amount of camphor sulfonic acid in the oil, heating to a temperature around 440 F., continuing the heating as long as steam bubbles form, and thereafter bodying the oil by exposure to heat between 550 and 600 F.

5. The process oi. claim 4 in which the acid is removed prior to bodying.

6. The process of claim 4 in which the acid is neutralized prior to bodying.

7. The process of claim 4 in which the camphor sulfonic acid is present as such in the bodying stage.

ALEXANDER SCHWARCMAN. 

